Shack-Hartmann 波前传感器质心探测的优化方法

为提高Shack-Hartmann(S-H)波前传感器的光斑质心探测精度，在分析质心探测误差来源的基础上，提出基于模板匹配的探测窗口选取方法和基于单个光斑的自适应阈值选取方法，将这两种方法与加权质心算法相结合求取质心，提高了质心探测精度。与固定阈值和传统质心算法相比较，当SNR 大于3 时，质心探测精度平均提高了约40%。将文中的方法应用于可见光波段的商品S-H 波前传感器，实验表明:文中方法得到的质心偏离度由传统方法的0.83 pixel 的最大值减小至0.15 pixel。该工作有重要的应用价值。

Optimization method for the centroid sensing of Shack-Hartmann wavefront sensor

In order to improve the centroid sensing accuracy of spot image of Shack-Hartmann wavefront sensor (S-H WFS), the error sources of centroid detection were discussed in the paper. The influence of detection window, threshold selection and centroid algorithm on centroid detection accuracy was analyzed. On this basis, detecting window selection method based on template match and adaptive threshold selection method based on single spot were proposed. The methods proposed in this paper were combined with the center of weight algorithm for improving the centroid detection accuracy. The accuracy with the comprehensive method increases 40% comparing with traditional method when signal-to-noise ratio(SNR) of the spot image of S-H WFS is more than 3. The methods was applied to a S-H WFS working in visible spectrum, the results showed that maximum centroid departure decreased from 0.83 pixel to 0.15 pixel. The work in this paper has a high value of practical application.